控制台檢查單選按鈕

Question

我試圖用 JS 來控制一個單選按鈕，以便查看選中按鈕的值。 Js 似乎沒有語法錯誤，但它返回未定義：

這是 HTML：

 const firstName = document.querySelector('#FirstName'); const lastName = document.querySelector('#LastName'); const email = document.querySelector('#email'); const comments = document.querySelector('#comments'); let meeting1 = document.querySelector('#meetingtype1'); let meeting2 = document.querySelector('#meetingtype2'); let meeting3 = document.querySelector('#meetingtype3'); let meeting4 = document.querySelector('#meetingtype4'); let meeting; if (meeting1.checked) { meeting = meeting1.value; console.log(meeting = "1"); } else if (meeting2.checked) { meeting = meeting2.value; console.log(meeting = "2") } else if (meeting3.checked) { meeting = meeting3.value; console.log(meeting = "3") } else if (meeting4.checked) { meeting = meeting4.value; console.log(meeting = "4") } const submitform = document.querySelector('#submitform'); submitform.addEventListener('click', function() { console.log(` Name: ${firstName.value}, Last Name: ${lastName.value}, Email: ${email.value}, Comment: ${comments.value} Type of meeting: ${meeting}`); });

 <fieldset> <legend>Would you like to meet for?</legend> <label><input type="radio" id="meetingtype1" name=meetingtype value="coffee" > A coffee</label> <label><input type="radio" id="meetingtype2" name=meetingtype value="zoom"> A zoom meeting</label> <label><input type="radio" id="meetingtype3" name=meetingtype value="drive"> A drive to Eilat</label> <label><input type="radio" id="meetingtype4" name=meetingtype value="chef"> A chef meal</label> <button id="submitform" type="submit">Submit</button>

非常感謝！

Answer 1

由於您想在單擊按鈕時檢查值/將其記錄到控制台上，因此請確保在 EventListener 內部使用 if-else 語句，而不是在 function 外部使用。 如果按照自己的方式編寫 if-else-statement，它將在頁面第一次加載時執行。

要打印所選會議的當前值，請將 JavaScript 代碼更改為此。 我修改了您提供的代碼。

let meeting1 = document.querySelector('#meetingtype1');
let meeting2 = document.querySelector('#meetingtype2');
let meeting3 = document.querySelector('#meetingtype3');
let meeting4 = document.querySelector('#meetingtype4');
let meeting;

const submitform = document.querySelector('#submitform');

submitform.addEventListener('click', function () {
    if (meeting1.checked){
        meeting = meeting1.value;
    } else if (meeting2.checked){
        meeting = meeting2.value;
    } else if (meeting3.checked){
        meeting = meeting3.value;
    } else if (meeting4.checked){
        meeting = meeting4.value;
    }
    console.log(`Type of meeting: ${meeting}`);
});